Running on 3 cylinders?

[clintcarr3]

Hi everyone. My bike seems to be running on 3 cylinders. While riding one day this past spring out of nowhere I lost a large amount of power it just didn't sound or feel right. The bike revs higher and rougher but accelerates much slower. Its the #4 cylinder, or furthest to the right when sitting on the bike, that is not running. I know this because after it has been running this header has no heat coming from it. However, this is only true most of the time. I have taken it on a few test rides and it will run very poorly as described but out of nowhere it will have full power and everything sounds and feels right again but only for a short amount of time before if begins to run rough again. It is a very precise and noticeable transition between the quality when it happens. When I feel full power kick in I can check that same header and there is heat coming from it. What could cause this? I know it is not the spark plug because I have changed it. I'm thinking it is the coil or wire connected to the spark plug that may be cutting in and out causing me to have this problem. How would i check this? Could it be a carb issue? It doesnt seem like it because power cuts in and out so quickly it seems as though it is an electrical problem. thanks in advance

[tony]

try your spark plug cap and plug although you have new plug check gap maybe change plug to another cylinder springs inside the cap deteriate failing that small drop of oil into cylider 4 to see if rings are down

[thatkid]

I'm thinking it is the coil or wire connected to the spark plug that may be cutting in and out causing me to have this problem. How would i check this?

Sounds very much like an electrical problem. You should check the coil secondary windings/plug wires, for #1 & #4.

The secondary windings are tested between the ignition/spark plug wires. Remove the spark plug caps (unscrew counter clockwise). Connect an ohm meter between #1 & #4 plug wires. factory spec is 9,600 to 14,400 Ohms.

Now check the spark plug caps, factory spec is 9.000 to 11,000 Omhs.

All readings should be checked when the coils/plug caps are cold I.E. 68 degrees F

[clintcarr3]

hey thanks for the input. I don't have an ohmmeter though and i don't know anybody with one i can borrow. I found a used set of 1&4 coil and wires for 10 bucks so i'm going to just see what happens when i change them out. Is there anything i need to know about changing the coil if if is another stock coil?

[thatkid]

Without an ohm meter, I would swap #4 plug cap with either of the cylinders that run fine, if #4 still doesn't fire then its not the plug cap, it could be the plug lead.

I would then connect #1 plug lead, to #4 spark plug and visa versa. The FZR uses waste spark, I.E. #1 & #4 spark simultaneously as do #2 & #3.

If #4 still doesn't fire, its not an electrical fault.

As far as i know the replacement #1 & #4 coil should fit, but for $10 is not a new coil. I hope the replacement solves your issue.

good luck

[clintcarr3]

wow, great advice! it must be the plug lead because when i tried changing the boot with #3 it was the same, then i switched 1&4 and it was #1 that wasn't firing. the new set should be here soon so i'll bet that fixes it. thanks!

[thatkid]

wow, great advice! it must be the plug lead because when i tried changing the boot with #3 it was the same, then i switched 1&4 and it was #1 that wasn't firing. the new set should be here soon so i'll bet that fixes it. thanks!

Your welcome.

[thatkid]

Well when i awoke this morning, i remembered that the plug leads/wires can be removed from the coil, apparently not easily though. Try cutting 1/4 inch off the bad lead then replace the plug cap, that may rectify the problem. That coil is still good so don't throw it away.